Should I be concerned if my boyfriend spends more time with his best friend than me?

So I love my boyfriend of 3 months but he has a really close relationship with his best friend. They practically live together and vary rarely have I seen them apart, (only when my boyfriend and I go on dates alone, which is like 1-2 times a month). I know my bf cares about me but its hard to get intimate when he's virtually attached to someone else. Sometimes it feels like I'm dating two guys just because I see his best friend so often. We all get along great and when the three of us hang out we don't have that third-wheeling problem-- but its still annoying how my bf spends way more time with his friend than me. I value their friendship and don't want to become in between it-- but at the same time, I don't want it to interfere with my relationship with my boyfriend. Any advice?